#include<iostream>
#include<opencv2/opencv.hpp>

using namespace std;
using namespace cv;

Mat srcImage;
Mat dstBoxFilter, dstBlur, dstGaussianBlur;
int g_BoxFilterValue = 1, g_BlurValue = 1, g_GaussianBlurValue = 1;
const int g_nMaxAlphaValue = 100;

//有滾動條事件時，可以進入回撥函式
void on_Trackbar(int, void *)
{
	boxFilter(srcImage, dstBoxFilter, -1, Size(g_BoxFilterValue + 1, g_BoxFilterValue + 1));
	blur(srcImage, dstBlur, Size(g_BlurValue + 1, g_BlurValue + 1));
	//高斯濾波必須是奇數值
	GaussianBlur(srcImage, dstGaussianBlur, Size(2 * g_GaussianBlurValue + 1, 2 * g_GaussianBlurValue + 1), 0, 0);

	imshow("方框濾波", dstBoxFilter);
	imshow("均值濾波", dstBlur);
	imshow("高斯濾波", dstGaussianBlur);
}

int main()
{
	srcImage = imread("牛吃草.jpg");
	dstBoxFilter.create(srcImage.size(), srcImage.type());
	dstBlur.create(srcImage.size(), srcImage.type());
	dstGaussianBlur.create(srcImage.size(), srcImage.type());

	g_BoxFilterValue = 0;
	g_BlurValue = 0;
	g_GaussianBlurValue = 0;
	namedWindow("方框濾波");
	createTrackbar("Value", "方框濾波", &g_BoxFilterValue, g_nMaxAlphaValue, on_Trackbar);
	on_Trackbar(g_BoxFilterValue, 0);
	namedWindow("均值濾波");
	createTrackbar("Value", "均值濾波", &g_BlurValue, g_nMaxAlphaValue, on_Trackbar);
	on_Trackbar(g_BlurValue, 0);
	namedWindow("高斯濾波");
	createTrackbar("Value", "高斯濾波", &g_GaussianBlurValue, g_nMaxAlphaValue, on_Trackbar);
	on_Trackbar(g_GaussianBlurValue, 0);

	waitKey(0);

	return 0;
}